The invention concerns an apparatus for skinning fish fillets, comprising a delivery element for delivering the fish fillets into the region of a skinning knife, the skinning knife for separating the skin from the fish fillet, a driver roller for the skin separated from the fish fillet, a contact pressure element having a means for controlling the position of the contact pressure element, and a discharge element for carrying away the skinned fish fillets. Furthermore, the invention concerns a method for skinning fish fillets, comprising the steps of: delivering a product stream composed of fish fillets on a delivery element, skinning the fish fillets by means of a skinning knife, deflection of a contact pressure element by the fish fillets during the skinning operation, a corresponding signal being triggered by deflection, and separately carrying away the skinned fish fillets on a discharge element on the one hand and the separated skin into a gap formed between a driver roller and the skinning knife on the other hand.
Apparatuses and methods of this kind are used in the fish-processing industry. Here, the fish fillets of different size or length are usually conveyed tail first on the delivery element into the region of the separating means. With the separating means the skin is separated from the fish fillet. During the separating operation the contact pressure element is deflected by the fish fillet body itself. Apart from the fact that the contact pressure element presses down the fish fillet and holds it down during the separating operation, the deflected contact pressure element also serves as a signal transmitter. As long as the contact pressure element is raised by the fish fillet, it is indicated that the skinning operation is not yet over. Only when the thicker head end of the fish fillet has completely left the separating means, does the contact pressure element drop back to its original position and so shows that the skinning operation is successfully completed. The apparatuses and methods can also be used to separate other surface layers, such as e.g. fat layers or the like, from fish or meat products, the direction of conveying the products being variable.
Apparatuses and methods as described above are known. However, with these apparatuses and methods there is the drawback that the fish fillets which are provided with bone or fin remains or other contaminants can catch on the skinning knife in practice. The result is then an accumulation of products at the skinning knife, which hinders processing, namely the skinning of subsequent fish fillets. This leads to faulty processing of the fish fillets, so that the skinned fish fillets are of only poor quality. There may also be a complete blockage in the region of the gap between driver roller and skinning knife, which leads to stopping of the product stream. The signal triggered by the contact pressure element is, however, not sufficient on its own to distinguish between a fault and a long fish fillet. To put it another way, the fact that the contact pressure element is deflected for longer than planned on the one hand could mean that there is a fault, and on the other hand could indicate that a particularly long product is being skinned. Accordingly a reliable statement cannot be made about the actual state of the product stream.